Can not close windows in interface
How to close view panels is well covered elsewhere. However in your particular case I would recommend clearing out the UI layout completely and starting from a clean setup.

To do this, save and re-open your .blend with Load UI disabled. You can disable Load UI persistently, by deselecting the option in &#9096; Ctrl&#9095; AltU> User Preferences > File, or temporarily, by deselecting the option available while opening a .blend:



Also note that opening a .blend with Load UI disabled will keep the current layout, so to get back to the default you will have to load your startup .blend (&#9096; CtrlN) first. Or if you want the default default, press File > Load factory settings before opening your .blend with Load UI disabled.